Mechanism for stacking sheet material



June 29,' 1954 c. G. PRI-:ls Erm. 2,682,344

MECHANISM FOR STACKING SHEET MATERIAL Filed Aug. 5, 1947 3 Sheets-Sheet 1 E ATTORNEYS June 29, 1954 c. G. PREIS EAL 2,682,344

MECHANISM .FOR STACKING SHEET MATERIAL Filed Aug. 5, 1947 3 Sheets-Sheet 2 June 29, 1954 c. G. PRI-:ls ETAL 2,682,344

MECHANISM FOR sTAcxING SHEET MATERIAL Filed Aug. 5, 1947 3 Sheets-Sheet 3 Patented June 29, 1954 MECHANISM FOR STACKING SHEET MATERIAL Carl G. Preis, Forest Hills, N. Y., and Ronald E. J.

Nordquist, Maplewood, N. J., assignors to American Can Company, New York, N. Y., a corporation of New Jersey Application August 5, 1947, Serial No. 766,340

14 Claims.

The present invention relates to a mechanism for stacking sheet material and the like and has particular reference to devices for arranging sheets in stacks of a predetermined number of sheets and for conveying the stacks to a suitable place oi deposit. rlhis is a companion application to our copending United States applications Serial Number 766,341, filed August 5, 1947,now Patent No. 2,594,346, issued April 29, 1'952, and Serial Number 766,342, filed August 5, 1947, now Patent No. 2,5e2,055, issued February 20, ,1951, and Serial Number 766,343, filed August 5, 1947, now Patent No. 2,629,502, issued February 24, i953, on Mechanism for Loading Sheet Material into Magazines.

An object of the invention is the provision of a mechanism for stacking sheet material wherein orderly stacks of a predetermined number of sheets may be assembled and gently transferred to a conveyor for delivery to a suitable place of deposit in a manner which facilitates rapid `and automatic handling of such material.

Another object is the provision of such a sheet stacking mechanism wherein diierent kinds of sheets may be arranged in dii-ferent stacks at different rates of speed and handled in the same manner for delivery to diierent suitable places of deposit.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which, taken in connection with the accompanying drawings, discloses a preferred embodiment thereof.

Referring to the drawings:

Figure l a side elevation of a sheet stacking mechanism embodying the instant invention, with parts broken away and parts shown in section;

Fig. 2 is a view similar to Fig. 1 and shows a fragmentary portion of the mechanism in that Jligure with certain of the parts i-n a different position;

Fig. 3 is a tcp plan view of the mechanism shown in Fig. l, with parts broken away;

Fig. 4 is a sectional view taken'substantially along the broken line i-ti in Fig. 3, with parts broken away;

Fig. 5 is an enlarged sectional view of the portion of the mechanism shown at the left in Fig, 1, with parts broken away; and

Fig. 6 is a composite schematic view of the principal mechanical parts and wiring diagram of the electric system used in the mechanism.

As a preferred embodiment of the instant invention the drawings illustrate a mechanism for stacking sheet metal strips, such as tin plate or the like material, from which containers or container parts or other articles are subsequently produced, although the invention is equally well adapted to stack other kinds of sheet material lor other uses. In the production of can ends, as an example, sheets A (Fig. 5) 'of tin plate are cut into double row strips B (Fig. l) and single row strips C prior to the cutting and forming of the can ends therefrom as disclosed for instance in United States Patent 1,920,999, issued August S, i933, to J. l-l. Murch on Shearing Machine. Each sheet usually is cut into a plurality of double row strips B and one single row or butt strip C, the latter being the last strip cut from the sheet.

ln the instant mechanism, by way of example, the sheets are cut into ive double row strips B and one single row strip C. These different types of strips are arranged in different stacks. When iifty strips have been collected in a stack of either type of strip, the stack is deposited on a conveyor and delivered in timed relation to any suitable place oi deposit. Each type of strip has its own conveyor and is delivered to its own place of deposit.

The sheets A are cut into the strips B, C in a scroll shear il (Figs. l and 5) which may form a part of the instant mechanism and which is cf the typ-e disclosed in the above mentioned lvlurch patent. In this scroll shear, a sheet A is advanced along a horizontally disposed table l2 in a step-by-step or intermittent manner by a pair of spaced and parallel reciprocating feed bars i3 having sheet advancing dogs [Ll secured thereto at spaced intervals for engagement behind the back edge of the sheet. Reciprocation of the feed bars i3 advances the sheet between a lower stationary shearing die i6 and a cooperating upper movable die or punch Il, the latter of which is reciprocated vertically in time with the advancement of the sheet as disclosed in the above mentioned Murch patent. This is a conventional scroll shear.

The rst cut taken on a sheet A is usually a trim cut and removes a slender trim edge or strip which is waste or scrap material. This trim strip falls from the stationary die i6 onto a chute 2l (Figs l and 5) which directs the strip to a waste bin for subsequent disposal as desired.

Following the trim cut, ive double row strips B are out from the sheet A. As each strip B is cut from the she-et it falls from the front edge of the die onto a plurality of endless delivery belts (see also Fig. 3) disposed adjacent the delivery end of the scroll shear and arranged in a declining position. The delivery belts 25 are carried on pairs of spaced idler pulleys 26 and driving pulleys 21.

The idler pulleys 26 are mounted on short idler shafts 28 journaled in bearings formed in the upper ends of a plurality of inclined belt brackets 29. The driving pulleys 21 are mounted on a long driving shaft 3| which is journaled in bearings formed in the lower ends of the belt brackets 23. This driving shaft is continuously rotated in any suitable manner preferably by connection with the scroll shear and at a speed fast enough to deliver the strips B from the shear without interference with each other.

There are three parallel belt brackets 28 arranged adjacent the delivery end of the scroll shear and they are mounted on a pivot shaft 33 (Figs. l, 2, 3 and 4) the ends of which are carried in bearing brackets 34 bolted to a frame 35 of a strip stacking device disposed adjacent and connected with the scroll shear The belt brackets are tied together by a tie rod 38 which extends through the brackets and which terminates in a pair of rocker arms 31 mounted on the pivot shaft 33 adjacent its ends.

A double row strip B, received on the delivery belts 25 extends transversely of the belts and is carried by the belts toward a short table 4| (Figs. 1, 2, 3 and 4) which extends across the mechanism adjacent and between the belt driving pulleys 21. The outer ends of the table 4| are secured to a pair of vertical brackets 42 which are bolted to the mechanism frame 35. The table terminates adjacent a stacking device E (Figs. 2 and 4) which includes a plurality of pairs of cooperating oppositely disposed L-shaped stack holding fingers 45, 46 which partially dene a main magazine F for the strips B. These holding fingers are mounted on a pair of spaced and parallel shafts 41, 48 (see also Fig. 2) the ends of which are carried in bearings 49 formed in the vertical brackets 42.

Hence when a double row strip B falls onto the delivery belts 25, and is carried forward toward the table 4|, it gathers suicient momentum that when it is delivered onto the table, it slides across the table and falls into the magazine F. rIhe delivered strip is caught by the L- shaped holding ngers 45, 46 and is held in a horizontal position as best shown in Fig. 2. As additional strips are received in the magazine they build up into a stack which is supported by the holding ngers. Angularly disposed guides 50 (Fig. 3) located within the magazine F align the strips endwise as they fall into the magazine.

When ve double row strips B have been cut from a sheet A and delivered into the double row strip magazine F, the delivery belts 25 are tilted into a further inclined position as best shown in Fig. 2 for the delivery into a different magazine of the next following strip, which is a single row or butt strip C. This lifting of the delivery belts 25 is brought about by a pair of cam rollers 52 (Figs. 1, 2 and 3) which are carried on the rocker arms 31. These two cam rollers 52 ride on a pair of continuously rotating cams 53 having a high spot 54 and which rotate at the rate of one revolution for each sheet A. These cams support the delivery belt brackets 29 in their normally inclined position.

The cams 53 are mounted on and are rotated by a transverse cam shaft 55 which is journaled in bearings 56 formed in the bearing brackets 34. One end of the shaft carries a driving sprocket 51 (Fig. 3) which is driven by an endless chain 58 in any suitable manner from the scroll shear At the completion of the cutting of the ve double row strips B from a sheet A, the high spots 54 of the cams 53 engage the cam rollers 52 and thus lift the delivery belt brackets 28 and the belts 25 into the position shown in Fig. 2. While the brackets and belts are in this raised position the last or single row strip C which is left in the die I6 when the fifth double row strip is cut, is advanced by the foremost scroll shear feed dog |4 across the die I6 and falls onto a stationary chute 6| disposed under the belts.

The single row strip C slides down the chute 6| into a single row strip or auxiliary magazine G (Fig. 4) which is disposed below the double row strip or main magazine F and like this magazine is dened partially by a plurality of pairs of cooperating oppositely located L shaped stack holding fingers 62, 63. These lingers are mounted on a pair of spaced and parallel transverse shafts 64, 65 having their ends carried in bearings formed in depending brackets 65 secured to the mechanism frame 35.

Since five double row strips B and only one single row strip C are cut from each sheet A, only ten sheets must be fed through the scroll shear to accumulate a stack of fty double row strips B while fifty sheets must be fed to accumulate a similar stack of single row strips C. When a stack of fifty of the double row strips B has accumulated in the magazine F, the holding fingers 45, 46 are moved outwardly and this per mits the entire stack to fall. The falling stack is received on a vertically movable stack transfer means or sectional platform 68 which extends across the mechanism just below the magazine F as shown in Figs. 2, 3 and 4.

Movement of the holding fingers 45, 46 is effected by lever arms 1|, 12 (Figs. l and 3) which are mounted on the outer ends of the finger shafts 41, 48. The lever arms are connected by an adjustable cross link 13 in such a manner that the shafts will rock in opposite directions when the link is shifted. The lever arm 12 is formed with a depending lever 14 which is connected by a link 15 to a piston rod 16 having a piston 11 (see Fig. 6) which operates within an air cylinder 18 secured to the adjacent bracket 42.

The cylinder 18 adjacent its ends is connected by pipes 8|, 82, to a slide valve housing 83 containing a slide valve 84 having a central feed channel 85. One end of the valve housing is open. Its opposite end, beyond the slide valve is provided with a vent opening 86. At this vented end of the housing the valve is backed up by a compression spring 81 interposed between the valve and the closed end of the housing. Opposite the pipes 8|, 82, the valve housing is connected to an inlet pipe 88 which is always in communication with the central feed channel of the slide valve and which leads from any suitable source of compressed air.

The slide valve 84 is periodically reciprocated within its valve housing 83` by a normally deenergized electric solenoid 9| which is alternately energized and deenergized through suitable electric circuits which Will be hereinafter ex plained in connection with the wiring diagram in Fig. 6. When the solenoid 8| is energized, it shifts the slide valve 84 from the position shown in Fig. 6 toward the right as viewed in that gure where the pipe 8| as well as the inlet pipe 88 is in communication with the central feed channel 85 of the valve.

In this position of the slide valve 84, air under pressure from the inlet pipe 88, flows through the valve channel 85 and pipe 8| into the cylinder 'I8 in front of the piston 1l and thus pushes the piston toward the left as viewed in Fig. 6. The moving piston forces any air that may be behind it, out of the cylinder through the pipe 82 and the open end of the valve housing This movement of the piston, rocks the links lil, 'l5 and the lever arms 1|, T2, 'I4 and thus opens or spreads apart the stack holding fingers t5, it to release the stack of double row strips B.

As soon as the stack of strips B fall out ci the magazine F onto the platform EB, the holding ngers 45, 46 immediately close to catch and retain the subsequently cut strips B to form another stack. This return movement of the holding fingers is eifected by an immediate deenergization of the solenoid 9| and a return of the slide valve 84 to its original position under A the force of the spring 8l. Inv this position ci the valve its feed channel 85 is in communication with thepipe 82 as well as the inlet pipe 812 while the pipe 8| is in communication with the port 86 of the valve housing 83.

Thus air under pressure flows from the inlet pipe 88 through the valve feed channel 35 and pipe 82 into the cylinder 'i8 behind the piston 'el and pushes the piston toward the right as viewed in Fig. 6. Air in the cylinder in front of the piston is expelled through the pipe 8|, valve housing 8S, and vent opening Sii, to the atmosphere. It is this movement of the piston that closes the holding ngers 45, i6 for the building up of another stack of strips B.

The sections of the platform ii which receive the stack of double row strips B from the magazine F are secured to a support plate Sil (Figs. 3 and 4) attached to a vertically movable slide t5 which operates in a vertical slideway 96 formed in a transverse bracket Sl having its outer ends secured to the mechanism frame 35. The slide is periodically lowered and raised by a bell crank lever 93 which is mounted on a pivot pin 9S carried in a bracket Il!!! secured to two of a plurality of horizontal chain rails |04 secured to the cross beams H12 of the mechanism frame 35.

One leg of the bell crank lever 98 is engaged in an opening |03 in the slide 95. The other leg is connected by a link it to a piston rod Isl having a piston Hi8 (see Fig. (i) which operates in a cylinder m9 of a conventional oil gear system which circulates oil or any other suitable iiuid under pressure through the system. For

this purpose the cylinder les adjacent its ends is connected by oil pipes H2 to a slide valve housing H3 containing a reciprocable slide valve l I4 having a central feed port I l5 and a pair of end vent ports Hii, lll.

Opposite the pipes H2, the valve housing H3 is connected to a main feed pipe H8 which is always in communication with the valve feed port lit and which leads from a source of oil under pressure. This side of the valve housing is also formed with a pair of vent channels lis, E2@ which connect with a main return pipe ifi which leads to any suitable place of discharge or reuse of the circulated oil.

The slide valve H4 is reciprocated in its housing M3 by a normally deenergized electric solenoid E which is alternately energized and deenergized by suitable electric circuits which will be hereinafter explained in connection with the wiring diagram in Fig. 6. When the solenoid is energized it shifts the slide valve H4 from the (Lil position shown in Fig. 6 to a position toward the left where the oil pipe as well as the main feed pipe I8 is in communication with the valve feed port H5.

With the valve llt in this position, oil under pressure from the main feed pipe iis iiows through the valve port H5 and pipe lil into the cylinder |69 behind the piston |58 and thus pushes the piston toward the right as viewed in Fig. 6. Any used oil which is in the cylinder in front of the piston is pushed out through the pipe H2, aligned valve vent port H5, and vent channel llt into the main return pipe |2i. This movement of the piston carries the platform t8 down into a depressed or stack delivery position.

After delivering the stack of strips B, the platliorrn is immediately raised to its original position by a deenergizing of the solenoid |25. This shifts the slide valve lit back into its original position as shown in Fig. 6. With the valve in this position, oil under pressure from the main feed pipe |18 flows through the valve feed port H5 and pipe |l2 into the cylinder it in front of the piston |53 and this pushes the piston and the platform connected therewith, back into their original positions. The used oil in back of the piston is expelled through the pipe lli, aligned valve vent port Hl, and vent channel |28 into the main return pipe 12| for discharge or reuse.

During the downward movement of the stack loaded platirom 63, it delivers the stack onto a conveyor H (Fig. 3) which includes a plurality of endless chains |28' (Figs. l and 4) which carry short stack supporting flats or treads lid. There are four of these chains |28 and they are disposed between the sections or the platform Ein. These chains operate over sprockets i3! mounted. on cross shafts |32 journaled in bearings |33 formed in the mechanism frame 35. The chains are actuated continuously or intermittently as desired, in any suitable manner in time with theother moving parts of the mechanism.

Hence as the platform @t moves down into a delivery position as mentioned above, it passes down below the upper runs of the conveyor chains |28 and thus deposits or delivers the stack oi double row strips B onto the treads im of the conveyor. While the platform is in this depressed or lowered position the conveyor carries the trans-- ierred stack away from the region of the platform to permit immediate return of the platform to elevated position. The conveyor carries stack of strips B to any suitable place of deposit. This completes the cycle of operations on thc double row strips B.

In a similar manner, the single row stack of strips C is transferred from their magazine G (Fig. e) to an endless belt conveyor i3@- which disposed under the magazine. This belt conveyor is actuated in any suitable manner and operates over a pulley i3? (Fig. l) mounted on a shaft its carried in bearings formed in a subframe i3d disposed between the scroll shear i l and the mechanism frame 35.

When a stack of fifty single row strips C have accumulated in the magazine G, the single row holding fingers t2, 63 are opened or moved outwardly and this'perrnits the entire stack to fall directly onto the conveyor |35 to be carried away `to any suitable place of deposit. This opening ci the stack holding fingers 62, t3 is effected by lever arms lill, |452 (Fig. l) secured to the finger shafts Se, 65. The lever arms are connected by a cross link |43. The lever arm |42 is formed with a lever |45 which is connected by a link |46 to a piston rod |41 having a piston |48 (Fig. 6) which operates in an air cylinder" |49 similar to the air cylinder 18.

Like the air cylinder 18, the cylinder |49 is connected by air pipes I |52 to a slide valve housing |53 containing a slide valve |54 having a central feed channel |55 which is always in communication with an inlet pipe |56 leading from a suitable source of supply of compressed air. The slide valve is periodically actuated by a normally deenergized electric solenoid |58 which is alternately energized and deenergized through suitable electric circuits which will be hereinafter explained in connection with the wiring diagram in Fig. 6.

When the solenoid |58 is energized it shifts the slide valve |54 from the position shown in Fig. 6 into a position which brings the pipe |5| as well as the inlet pipe |56 into communication with the valve feed channel |55 and this permits air under pressure to flow into the cylinder |49 in back of the piston |48 and thus push the piston up as viewed in Fig. 6. It is this movement that opens the stack holding fingers 62, 93. Air in front of the piston is expelled through the pipe |52 and a communicating open end of the cylinder.

As soon as the stack of single row strips C has fallen from the magazine G, the holding fingers 62, 63 immediately close for the forming of a new stack. This is effected by a deenergizing of the solenoid |53 and the force of a spring |59 upon the valve. Deenergizing of the solenoid shifts the slide valve |54 back into its original position as shown in Fig. 6 and this permits air under pressure to flow from the inlet pipe |56 through the valve feed channel |55 and pipe |52 into the cylinder |49 in front of the piston |46. This air pushes the piston down and thus closes the holding ngers 62, 63. During this movement of the piston, any air that may be in back of it, is expelled through pipe |5| into the closed end of the valve housing from which it escapesl through a vent port |60 in the housing. This completes the cycle of operations incident to forming and delivering a stack of single row strips C.

Reference should now be had to the wiring diagram in Fig. 6 which discloses schematically the various electric circuits which control the operation of the solenoids 9|, |25, |58 hereinbefore mentioned, and which transmit electric current from any suitable source of supply, such as a generator |10. These circuits are established through the closing of a normally open triple pole electric switch |1| which is closed and opened by a continuously rotating edge cam |12 having a sharp high spot or actuating protuberance |12 formed thereon.

The cam |12 is rotated at the rate of one revolution for every ten sheets A, i. e. one revolution for every fifty double row strips B or every ten single row strips C'. For this purpose the cam is mounted on and is rotated by a short shaft |14 (see Figs. 1 and 3) journaled in bearings formed in the adjacent bracket 34. The shaft is drivenby a gear |15 which is mounted thereon and which meshes with a speed reducing pinion |16 carried on a short shaft |11 journaled in bearings in the bracket 34.

The pinion |16 is driven by and is formed integrally with a gear |18 which meshes with a second speed reducing pinion |19 mounted on a short shaft |80 journaled in bearings formed in the bracket 34. This pinion is formed integrally with and is driven by a gear |8| which meshes with a driving pinion |82 carried on the cam shaft 55 which makes one revolution for each sheet A fed into the scroll shear I. Through this gear train the cam |12 makes one revolution for each stack of double row strips B and thus momentarily closes the triple pole switch |1| for each stack upon completion of its assemblage.

Upon the closing of the switch |1| a circuit R is immediately established which includes the stack holding finger solenoid 9| (Fig. 6). One side of this solenoid is connected by a wire |85 to a main lead wire |86 of the generator |10. The opposite side of the solenoid is connected by a wire |81 to a contact |88 of the switch |1|. An opposite contact |89 is connected by a wire |98 to a main return Wire |9| of the generator. Current passing along this circuit, when the switch |1| is closed, energizes the solenoid 9| and thus through the slide valve 84 and air cylinder 18 opens the stack holding fingers 45, 46 as hereinbefore explained.

Opening of the stack holding fingers 45, 46 establishes a circuit S which includes a normally open finger switch |95, a normally closed platform switch |96, and a normally deenergized solenoid |91. In this circuit the generator lead wire |86 is connected by a Wire |98, to one side of the solenoid |91. The opposite side of the solenoid is connected by a Wire |99 to the finger switch |95. The finger switch is also connected by a Wire 200 to the platform switch |96 which is connected by a wire 20| to the generator return wire |9|.

When the stack holding fingers 45, 46 momentarily open, the finger 45 engages and momentarily closes the finger switch |95. This is done during the momentary period in which the triple pole switch |1| is still closed. Electric current immediately flows from the generator along the circuit and energizes the solenoid |91. The energizing of the solenoid immediately closes a normally open holding switch 205 which establishes and holds a platform circuit T. Closing of the holding switch 205 cuts out the finger switch |95 and the triple pole switch |1| and thus permits these switches to open Without affecting the platform circuit.

While the holding switch 205 is closed, electric current from the generator |10 flows along the generator lead wire |86, and Wire |98 through the solenoid |91 and along wire |99 to and through the switch 205, then along a connecting wire 206 to and through the platform solenoid |25, thence along a connecting wire 201, through the platform switch |96 and returning along wire 20| to the generator return wire |9|. This current energizes the platform solenoid |25 and thus through its slide valve ||4 and oil cylinder |09, lowers the platform 68 for the delivery of the stack of strips B onto the conveyor E as hereinbefore explained.

Upon delivery of the stack B to the conveyor, the platform 68 engages and opens the platform switch |96 and this breaks the holding circuit T. The solenoids |25, |91 thereupon become deenergized and thus the platform returns to its normally elevated position and the holding switch 205 opens in readiness for the next stack operation. This completes the operations incidental to the delivery of the stack of double row strips B.

Since there is only one stack of fty single row strips C formedV for every five' stacks of the double row strips B, the electric circuits which control the release of the single rowstack are arranged to operate every fth time the cam H2 closes the triple pole switch lll. ThisV is brought about by a conventional rotary switch or time delay device 2li which is provided with an intermittently rotatable contact ringer Elli which as it rotates successively engagesy against a series of ten contacts 2l-3 numbered 0 to 9' inelusive'. The finger is rotated; throughthe usual pawl and ratchet arrangement actuated by a magnet 215 whichl is connected by wires Zit, 2H respectively to the generator lead wire let and a contact 2`l3 of the triple pole switch lli. A3 cooperating contactY 2l9 is. connectedr by a wire 220 to the generator return wire I9I.

Hence every time the switch IVII closes, as eX- plained! above in connection with the circuits controlling the stacks of double rowstrips B, it energizes the magnet 2,15 and this advances the rotary switch finger ZIE` fromv engagement with one ofthe contacts 'Mft-k into engagement with the next succeeding contact; During this stepped advancement of the finger, nothing happens until the finger engages with one or the other of the contacts marked and` 5. This occurs after every ve advancements of the linger.

Engagement of the'V rotary finger 2li with contact 0101' 5 of the contacts 213 establishes a circuit V which includes the solenoid tt. In this circuit the generator lead wire E36V is connected by a wire 225` toone side of the solenoid while the opposite side is connected by a wire 25261 to the contacts 0TA and 5Y of the contacts 2F31 The rotating finger is connected by a wire 2125i to a contact 22SA of the triple pole switch lll. A cooperating contact 2290i the switch is connected by a wire 23G- to the generator returny wire will Hence when the triple pole switch ilfl closes simultaneously with the engagement of the r0- tary switch nger M2 with either7 ofthe contacts Oto of contacts 213, the circuit 'v' becomes closed or established? and this energizes the solenoid IES. Energizing of this solenoid opens the stack fingers $2-, (i3 and thus del-iversthe stack of single row strips C` onto its discharge conveyor ist'v as hereinbefore explained; Since the energizing of this solenoid is of a momentary duration, thel stack holding ngers open and close rapidly, the return being effected by the spring i591 assoon as the solenoid is deenergized: by the opening of the triplev pole switch lll". This completes the operations incidental to the` de'- livery of the stacksv of single rowv strips ItA is' thought that the invention and many of its attendant advantages willbe understood from the foregoing description, andi it will be apparent that various changes may be made in the form, construction and arrangementof the partswith-A out departing fromthe spirit and' scope off the invention or sacrificingl all of its: material advantages, the form hereinbefore described being merely a preferred embodiment thereof.

We claim-z l. In a mechanism for stacking sheet material; the combination of a magazine for receiving sheets of material, movable' holding elements in said magazine for retaining the sheets inplace thereinv ink stacked formation, means connected tol said1 holding` elements and operable when a stack of a predetermined: number of sheetshas been'` built upinsalidm'agazine for withdrawing said' holding elements from said magazine` and' releasing thestack of sheets therefrom, a con-` tinuously moving conveyor-disposed below said magazine for receiving the released stack 0f sheetsV and for carrying it to a place of deposit, a platform mounted for vertical reciprocation beneath said magazine for receiving the released stack of sheets therefrom when the platform is in elevated position, means actuated by said holding elements in their movement to stack releasing position for depressing said platform to ransfer said stack of sheets to said conveyor, said platform depressing means being further actuated by the platform when in depressed position to elevate the platform for a succeeding stach transfer operation. l

2. in a mechanism for stacking sheet material in the form of wide and narrow cut strips delivered from a sheet cutting mechanism, the combination of a main magazine for receiving said iii/ide" strips, movable means adjacent said magazine for directing the wide strips into said magazine, an auxiliary magazine for receiving said narrow strips, means for shifting said movable means for diverting the narrow strips into said auxiliary magazine, holding elements in said magazines for supporting the strips received therein in stacked formation, and primary timing means for withdrawing the holding elements from one of said magazines to release a predetermined quantity of strips therefrom, and secondary timing means operable by said primary 'ti-ming means for withdrawing the holding elements from the other magazine to release a predetermined quantity of strips therefrom.

3. In a mechanismA for stacking sheet material, the combination of a magazine for receiving cut strips from a sheet cutting mechanism, movable holding elements insaid magazine for supporting the strips in stacked formation, conveyor means for receiving a stack of strips from said magazine, fluid pressure actuated means connecting with said holding elements and operable to witin draw saidhol'ding elements from said magazine to release the stack of strips therefrom when a stack of a predetermined number of strips has beenA built upi'n' said magazine, and means actuatedf by said holding elements when withdrawn from said magazine for delivering said stack of strips to said conveyor.

4; In a mechanism for stacking sheet material, tlieA combination of a magazine for receiving cut strips from'- al sheet cutting mechanism, holding means in said magazine for supporting the strips stacked`l formation, a conveyor for receiving successive stacks of strips from said magazine, fluid'I actuated means connecting with said holding means, electric means connecting with said uid actuated meansland controlling the operation" thereof, timingv means for controlling the operation of said electric means for withdrawing said holding means from said magazine to release the stack` of strips therefrom when a stack of a predetermined number of strips has been built up in. saldi magazine, and: means actuated by said holding-:meanszwhen-withdrawn from said magazine for delivering said stacl; of strips to said; conveyor.

5; l'n a'mechanismfor stacking sheet' material, the combination of a magazine for. receiving sheets of. material, movable holding elements in said' magazine for retainingI the sheets in place therein inv stacked formation, means operable when: a stack of a predetermined number of sheets has beenl builtl up in said magazine forwithdrawing said holding elements from said f' magazine to' release the staokfof sheets therefrom,

a conveyor disposedbelow said magazine for receiving the released stack of sheets and for carrying the same to a place of deposit, a vertically reciprocable platform disposed between said magazine and said conveyor for receiving the released stack of sheets from said magazine and for depositing said stack on said conveyor, fluid pressure means for reciprocating said platform, electric means connecting with said nuid pressure means and energized by said holding elements in their movement to stack releasing position to depress said platform toward said conveyor to transfer the stack of sheets thereto, and other electric means connected to said uid pressure means and energized by said platform in depressed position for returning said platform to elevated position after transfer of the stack therefrom to said conveyor.

6. In a mechanism for stacking sheet material, the combination of a magazine for receiving sheets of material, holding elements in said magazine for retaining the sheets in place therein in stacked formation, means operable when a` A tion and for depositing it onto said continuously moving conveyor while said platform is lowered, actuating means for operating said platform,

and electric means connecting with said actuating means and operable by said holding elements for controlling the operation of said platform.

'7. In a mechanism for stacking sheet material, the combination of means for feeding a predetermined number of wide strips and a predetermined number of narrow strips in repetitive order, a main magazine for receiving said wide strips, an auxiliary magazine for receiving said narrow strips, holding elements in each of Asaid magazines for supporting the strips received therein in stacked formation, separate sets of actuating means connecting with the holding elements of each of said magazines and operating said holding elements to release a stack of strips therefrom, electric means connecting with each set of actuating means, timing means actuated in synchronism with said feeding means for controlling the operation of said electric means to operate the holding elements of both magazines simultaneously when a predetermined number of strips have accumulated in one of said magazines, and a time delay device operated by said timing means through said electric means for withholding the operation of the holding elements of said one magazine until said predetermined number of strips have accumulated therein.

8. In a mechanism for stacking sheet material, the combination of a conveyor for feeding strips of different sizes from a supply of sheet material, a main magazine for receiving from said conveyor and for stacking therein all strips of one size, an auxiliary magazine for receiving from said conveyor and for stacking therein all strips of another size, fixed spaced means for directing said strips from said conveyor to said magazines respectively, means operable in time with said conveyor for moving the latter relative to said spaced directing means to selectively direct said strips to their respective magazines, holding elements in each of said magazines for supporting said stacks of strips therein, primary releasing means operable in time with said conveyor for withdrawing said holding elements of said main magazine to release the strips therefrom, and secondary releasing means operable at predetermined intervals by said primary releasing means to release the strips from said auxiliary magazine relatively to the release of strips from said main magazine.

9. In a mechanism for stacking strips of sheet material, the combination of a main magazine for stacking strips of one size, an auxiliary magazine for stacking strips of another size, means for feeding strips of different sizes and for distributing said strips to said magazines, a main magazine stack holding and releasing device, an auxiliary magazine stack holding and releasing device, each of said devices comprising movable fingers for holding the strips in stacks in the respective magazines, fluid operated means for moving said ngers into stack holding and stack releasing positions, a main solenoid for controlling the fluid operated means of said main magazine for moving the fingers in the main magazine into stack holding and stack releasing positions-an auxiliary solenoid for controlling the fluid operated means of said auxiliary magazine for moving the ngers in said auxiliary magazine into stack holding and stack releasing positions, a primary electrical switch operated in time with said feeding means for operating said main solenoid at predetermined time intervals to release a stack of strips from said main magazine at the end of each predetermined interval, and a time delay device including a second electrical switch operated under control of said primary electrical switch for energizing said auxiliary solenoid at predetermined time intervals relative to the intervals at which said main solenoid is operated, said stacks in the magazines being thus relatively released from said magazines at various intervals of time.

10. In a mechanism for stacking sheet material, the combination of a magazine for receiving sheets of material, a conveyor for receiving successive stacks of sheets from said magazine, movable holding means in said magazine for retaining the sheets in place therein in stacked formation, fluid pressure means connected to said holding means and operable when a stack of a predetermined number of sheets has been built up in said magazine for withdrawing said holding means from said magazine to release the stack of sheets therefrom, valve means connected to and controlling the operation of said fluid pressure means to withdraw said holding means from said stack, and means actuated by said holding means when withdrawn from said magazine for delivering said sheet stacks to said conveyor.

11. In a mechanism for stacking sheet material, the combination of a plurality of magazines for receiving cut strips from a sheet cutting mechanism, said magazines respectively receiving uniform strips of varying widths, spaced conveyor means for respectively receiving stacks of strips from said magazines, movable means in each of said magazines for supporting the strips received therein in stacked formation, means operable when a stack of a predetermined number of strips has been built up in one of said magazines for withdrawing said supporting means therefrom to release the stack of strips from said one magazine,

13 and means actuated by said strip supporting means When Withdrawn from one of said magazines for delivering said stack of strips to one of said conveyor means.

12. In a mechanism for stacking sheet material, the combination of a plurality of magazines for receiving cut strips of different widths delivered from a sheet cutting mechanism, each magazine receiving strips of a different predetermined width, movable means operable in time with the delivery of strips to said magazines for alternately and selectively delivering strips of uniform Width to said magazines respectively, holding means in each of said magazines for supporting the strips received therein in stacked formation, means operable when a stack of substantially the same predetermined number of strips has been built up in one of said magazines for withdrawing the holding means therefrom to release the stack of strips from said one magazine, conveyor means disposed beneath each of said magazines for receiving the stacks of strips as they are released therefrom and for carrying them to a place of deposit, and means actuated by a said holding means when withdrawn from its magazine for delivering said stack of strips released therefrom to one of said conveyor means.

13. In a mechanism for separately stacking strips of different sizes received from a sheet cutting mechanism, the combination of a rst magazine for receiving and stacking therein a preponderance of cut strips of one size, a second magazine for receiving and stacking therein a less number of cut strips of a different size, a movable conveyor disposed in advance of said magazines in the path of travel of the cut strips and in one position receiving and delivering said one size strips to said first magazine, means engageable with said movable conveyor for periodically shifting the same to another position out of the path of strip travel to divert said different size strips to said second magazine, means operative in time with the delivery of the out strips for actuating said conveyor engaging means to shift said movable conveyor for the described selective strip delivery to said first and second magazines, means for periodically releasing stacks of a predetermined number of said one size strips from said rst magazine, means for periodically releasing at less frequent intervals stacks of an equal number of said different size strips from said second magazine, and means responsive to the periodic release of strip stacks from said first magazine for actuating the stack release from said second magazine only after the same predetermined number of strips has accumulated therein.

14. In a mechanism for separately stacking strips of different sizes received from a sheet cutting mechanism, the combination of a rst magazine for receiving and stacking therein a preponderance of cut strips of one size, a second magazine disposed beneath said first magazine for receiving and stacking therein a less number of cut strips of a different size, a movable conveyor disposed in advance of said magazines in the path of travel of the cut strips and in one position receiving and delivering said one size strips to said first magazine, a fixed conveyor disposed beneath said movable conveyor for receiving and delivering said another size strips to said second magazine, a rotatable member engageable with said movable conveyor for periodically shifting the same to another position out of the path of strip travel to divert said different size strips to said second fixed conveyor and thence to said second magazine, means operative in time with the delivery of the cut strips for actuating said rotatable member to shift said movable conveyor for the described selective strip delivery to said rst and second magazines, means for periodically releasing stacks of a predetermined number of said one size strips from said rst magazine, means for periodically releasing at less frequent intervals stacks of an equal number of said different size strips from said second magazine, and means responsive to the periodic release of strip stacks from said first magazine for actuating the stack release from said second magazine only after the same predetermined number of strips has accumulated therein.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 918,084 Pancoast Apr. 13, 1909 1,318,910 Pfohl Oct. 14, 1919 1,365,741 Speer Jan. 18, 1921 1,412,795 Pfohl Apr. 11, 1922 1,600,958 Hart et al Sept. 21, 1926 1,798,017 Free Mar. 24, 1931 1,817,387 McCrery Aug. 4, 1931 1,920,999 Murch Aug. 8, 1933 2,045,046 Mudd June 23, 1936 2,076,186 Reynolds et al Apr. 6, 1937 2,146,581 Kaufman Feb. 7, 1937 2,228,887 Peterson Jan. 14, 1941 2,315,003 Martin et al Mar. 30, 1943 2,333,479 Graf Nov. 2, 1943 2,396,090 Curtis Mar. 5, 1946 2,414,059 Powers Jan. 7, 1947 2,540,971 Wagner, Jr. et al Feb. 6, 1951 

